Modification of textile material with methylolated lactams



United States Patent U.S. Cl. 8-1155 8 Claims ABSTRACT OF THE DISCLOSUREReaction of fibrous materials containing labile hydrogen atoms andheterogeneous blends thereof with N-methylol lactams or the lower alkylether derivatives thereof in the presence of an acid catalyst atelevated temperatures. Fibrous material dye affinity is modified.

The present invention relates to a method for treating fibrous materialsin order to improve the properties thereof and to the improved fibrousmaterials produced thereby. More particularly, the present inventionrelates to a method for improving the receptivity of fibrous materials,preferably of the cellulosic variety, including blends thereof withother fibrous materials of the natural and/ or synthetic types, todyestuffs and fluorescent brightening agents not ordinarily substantivethereto. This invention also relates to an improvement in such otherproperties of fibrous materials as resistance to attack by mildew,laundry souls and the like, and to shrinking, washing and the like.

As is well known, fibrous materials consisting in whole or in part ofcellulosic materials such as cotton and the like in general possess poorreceptivity for aconsiderable number of the commercially availabledyestuffs commonly employed in fiber coloring operations. For example,many of the dyestuffs which can be effectively employed with natural andsynthetic fibers such as wool, nylon, etc., possess little or noaflinity for cellulosic materials, at least to the extent of satisfyingthe requirements of commerce. Certain fiber-pretreatment methods haveheretofore been proposed by which the physical and/ or chemicalcharacteristics of cellulosic fibrous material are altered to therebyproduce a fibrous material.

allegedly characterized by improved receptivity to dyestuffs notordinarily substantive thereto. For example,

it has been previously suggested to treat fibrous materials at any stageof the coloring operation, i.e., before, during or after the dyeing stepwith polymerizable monomeric materials which are thereafter made toundergo polymerization in situ on and/or with the fibrous material, oralternatively, to treat the fibrous material directly with the resin insolution form. However, such methods suffer from several disadvantagesamong the more notable being the high cost of resin and resin-formingmaterials and the tendency of such materials to undesirably affect thecharacter and properties of fibrous materials treated therewith. It hasalso been suggested, as a method of improving dye receptivity, topretreat cellulosic fibrous materials with a compound which is reactivetherewith. However, fiber-treating methods based on the use of thereactive compounds thus far proposed, though enhancing somewhat theproperties of fibrous materials treated therewith, leave much to bedesired with respect to such desirable properties in the resultant fiberas receptivity to dyestuffs, fluorescent brightening agents and the likeas well as resistance to attack by mildew, laundry sours and the like.

Accordingly, it is an object of this invention to provide a method forimproving the properties of fibrous mice materials which will not besubject to one or more of the above disadvantages.

Another object of this invention resides in the provision of fibrousmaterials having improved properties. Still other objects and advantagesof the invention will become further apparent from the followingdetailed description thereof.

p In accordance with the aforesaid objects of the invention, methodshave been devised for the achievement thereof which comprise treating afibrous material with an aqueous solution containing at least one lactamcompound selected from the group consisting of compounds of the formula:

onion and ring carbon-lower alkyl substituted derivatives thereof,wherein R represents an alkylene bridge such as, for example, ethylene,propylene, butylene, necessary to complete a S to 7 memberedheterocyclic ring; and R represents hydrogen or lower alkyl such asmethyl, ethyl, propyl and the like; and subsequently drying and curingthe treated material at a temperature of at least about C. The inventionalso comprises the provision of fibrous materials having improvedreceptivity to dyestuffs which ordinarily display but negligibleaflinity for cellulosic fibrous materials such as those employed incoloring wool, nylon and the like. Moreover, it has been found that whenfibrous materials are treated according to the present invention thereis obtained a fiber product,

which exhibits, in addition to the improved properties of theabove-described type, surprisingly good receptivity to fluorescentbrightening agents.

This result is particularly significant since many of the syntheticfibers and their blends with cellulosic materials as typified, forexample, by nylon-cotton, Dacron-cotton, acrylic-cotton and the like,have proved relatively difficult to whiten to the desired extent.

A preferred class of compounds for use in the present invention,particularly for improving the receptivity of fiber materials todyestuffs and fluorescent whiteners, is the class of compounds of theabove formula wherein R represents the carbon atoms necessary tocomplete a 2-pyrrolidone ring, i.e., R in the above formula is ethylene.These compounds can be structurally depicted as follows:

II I

CH C=O and the ring carbon-lower alkyl substituted derivatives thereof,where R is hydrogen or lower alkyl. These compounds can be easily andconveniently prepared in known manner from the parent pyrrolidone. Thecompound of the above formula wherein R is hydrogen, i.e.,N-hydroxymethylpyr-rolidone, is formed by reacting 2-pyrrolidone with.paraformaldehyde in the presence of an alkaline catalyst such aspotassium hydroxide. Com pounds of the above formula where R is loweralkyl can be formed by reacting Z-pyrrolidone with a mixture ofparaformaldehyde and an alcohol.

The compounds of Formula I above 'wherein R represents the carbon atomsnecessary to complete either a Z-piperidone or -caprolact am ring, i.e.,R is propylene or butylene, respectively, are also highly effectiveagents for increasing the dye and fluorescent brightener recep- 3.tivity of fibrous materials treated therewith. The compounds can bestructurally depicted as follows:

111 CHz-CIIzCHzCHz IV CHz(CHz)aCH 1% :0 i1 e=0 CH2 0 R 1112 O R(N-methylol piperidone) (N-methylol caprolactam) as well as the ringcarbon-lower alkyl substituted derivatives thereof, wherein R ishydrogen or lower alkyl. Compounds of the above formulae can be preparedby N-methylolation or N-alkoxymethylation of the parent piperidone-2 and-caprolactam compounds in the same manner as described in connectionwith the preparation of the compounds of Formula II hereinabove.

The process of the present invention is applicable in general to fibrousmaterials constituted in whole or in part by labile hydrogen-containingsubstances such as cotton and other materials of the cellulosic type. Asillustrative of the foregoing class of materials there may be mentionedtextiles comprising 100 percent cotton, linen and the like and blends offibers of cellulosic materials with fibers of other materials such asregenerated cellulose, e.g., viscose rayon or cuprammonium rayon,polyamides such as nylon, e.g., the polyamide of hexarnethylene diamineand adipic acid or of 6-aminocaproic acid; polyurethanes; acrylonitrilepolymers and copolymers; polyesters such as polyethylene terephthalate;animal fibers such as wool and mohair; cellulose esters, e.g., celluloseacetate, cellulose propionate, cellulose butyrate, celluloseacetate-propionate, cellulose acetate-butyrate and the like andcellulose ethers such as ethyl or benzyl cellulose.

In carrying out the method of the present invention according thepreferred manner, an aqueous medium containing at least one lactamderivative of the type depicted in the foregoing formulae is applied tothe fibrous material, following which the material so treated is driedand cured. The aqueous medium may be in the form of a solution,emulsion, suspension or other type of dispersion depending for exampleupon the physical properties of the particular lactam derivativeemployed, Although the lactam derivatives of the present invention areall readily water soluble or dispersible, it may in some instances bedesired to promote lactam solubility as for example by moderate heatingof the aqueous media. Moreover, the aqueous medium may further containany suitable stabilizer, surface active agent and the like to assist inproviding a suitably uniform medium for the fiber treatment. The aqueousmedium may in addition contain a swelling agent for the fibrous materialsuch as, for example, the butyl ether of ethylene glycol, acetone,dioxane and the like to promote conformity of distribution of the lactamderivative throughout the fibrous material.

Preferably, the aqueous treating medium is further. provided with anacid catalyst. Suitable catalysts are those which are acidic at thetemperatures employed when applying the lactam solution to the fibrousmaterial. As representative catalyst materials these may be mentioned byway of illustrationammonium phosphate, also known as accelerator 187,Zinc chloride and zinc nitrate and the like. Acid-bound alkanol aminessuch as 2-methyl-2-amino-l-propanol hydrochloride, also known ascatalyst A are particularly effective catalysts for carrying out thepresent invention. Other suitable catalysts are ammonium sulfate, oxalicacid and the amine hydrochloride known as Aerotex Accelerator 187 andthe like. The catalyst may advantageously be added to the aqueoustreating medium in the form of an aqueous solution just before themixture is applied to the textile material. Catalyst proportions are notparticularly critical and may range from about .1 percent to percent andhigher based on the weight of lactam. However, in certain instances, theamount of catalyst should be increased. For example, if an alkalinesubstance is present in the fibrous material, e.g., as an impurity, itwill probably poison the catalyst by reacting therewith, therebyreducing the effective amount of catalyst available for the fibertreatment. Accordingly, in such a case, the amount of catalyst should beincreased to provide the desired effective amount thereof.

The concentration of the lactam derivative in the aqueous medium is notparticularly critical and may range from about 0.5 to 50 percent andhigher, depending for example upon the method employed for applying themedium to the fibrous material, the particular lactam derivative andfibrous material employed, the properties desired in the fibrousmaterial, etc. The aqueous treat ing compositions may be applied to thefibrous material by immersion, padding, spraying, painting or any otherdesired manner, continuous or otherwise. When overall effects aredesired in the fabric material, it is preferred to apply an excess ofthe aqueous treating composition thereto followed by removal of excessas by squeezing, spinning, etc.

Following application of the aqueous solution of lactam derivative, thefibrous material is dried and then cured at a temperature of at leastabout C. The drying can be effected at temperatures of up to about 95 C.and higher, depending merely on the rate of drying desired. The durationof the curing step will in general vary inversely with the temperatureemployed although, of course, the temperature and time factors will alsodepend somewhat upon the type of fibrous material being treated, theparticular lactam treating agent employed, the results desired, etc. Inany event, the optimum curing parameters of time and/or temperature,may, in any particular instance, be readily determined by routineexperimentation. For example, as a general indication of the effect ofthe time temperature parameters on curing, it can be expected that thecuring time will usually range up to five minutes or more fortemperatures in the vicinity of approximately C.- C. with cottonmaterials, while the use of higher temperatures, e.g., up to 250 C. andhigher, reduce proportionately the curing time required toin someinstances-a matter of seconds. Following the curing opera tion, thefibrous material is desirably washed, preferably in the presence of amild detergent, to remove any residual acidity, etc., and prevent thedevelopment of odor.

The mechanism by which the process and compositions of the presentinvention yield fibrous materials having improved properties of the typeenumerated hereinabove is not completely understood but can bepostulated as follows. Apparently, the labile hydrogen atoms present inthe molecular structure of the fibrous material being treated enter intoreaction with the N-methylol or N-alkoxymethyl substituent of the lactamderivative. Apparently an initial hydrolysis reaction occurs with theN-alkoxymethyl derivatives whereby such groups are converted tomethylol. The labile hydrogen of the fibrous material may be present inthe form of hydroxy, carboxy, amido, amino and/or cyano (hydrolysisprovides amido and carboxyl hydrogen) and the like.

For example, the hydroxy groups may be present in the form of alkylol,e.g., methylol such as found in cellulose, its partial ethers and estersand cellulosic type materials such as cotton, or as glycol residuescontaining free hydroxy such as found in synthetic polyesters of thelinear variety or such groups in vinyl type synthetic polymers.Illustrative of the materials which contain and/ or provide labilehydrogen in the form of carboxy are the synthetic vinyl-type polymersknown as the acrylics, synthetic polymers of the polyester typecontaining free carboxy within the molecular structure thereof, andmaterials which contain functional groups convertible to carboxy underthe conditions of the treatment process described herein such as wooland polymers from acrylonitrile and the like. Illustrative of thematerials which contain and/or provide labile hydrogen in the form ofamino and amido under the conditions of the treatment process describedherein are vinyl type polymers containing recurring amino or amido sidegroups such as polyvinylamines, polyacrylamide, etc., wool, nylon,hydrolyzed acrylonitrile polymers, etc. In any event, it is quiteapparent that the lact-am derivatives of the present inventionchemically combine with the fibrous material being treated as evidencedby chemical analysis of the treated fiber product, application of severewash tests, etc., as will be apparent from the examples givenhereinbelow.

As stated hereinabove, the process of this invention is found to behighly effective for improving the properties of fibrous materialscontaining labile hydrogen within the molecular structure thereof, e.g.,cellulosic materials such as cotton and the like, synthetic and animalfibers of the type indicated hereinabove, and blends of two or more ofthe foregoing materials. The fibrous material may be in any of the usualforms, e.g., staple, fiber or continuous filament in bulk form or in theform of tow, rope, yarns, slubbings, warps, fabrics, felts, and thelike, and treated as a wound package, running length fibrous stock,bulk,

etc.

The fibrous materials obtained by the process of the present inventionexhibit a pronounced animalization effect which is probably due to thepresence therein of chemically bound nitrogen, e.g., in the form ofamide groups, resulting from the chemicalinteraction of the fibrousmaterial and lactam derivative. Accordingly, the resultant fibrousmaterial is characterized by many woollike properties, such as apronouncedreceptivity for acid dyes, basic dyes, wool dyes, etc.,fluorescent brighteners and the like.

The following examples are given only for purposes of illustrating thepresent invention and are not to be regarded as limitative thereof. Allparts and proportions referred to herein and in the appended claims areby weight unless otherwise indicated.

EXAMPLE 1 An aqueous solution containing parts ofN-hydroxymethylpyrrolidone and 0.36 part of the. catalyst 2-methyl-Z-a-mino-l-propanol hydrochloride, which is added in the form of a 25percent aqueous solution thereof, is applied by padding to cotton printcloth, 80 x. 80, at room temperature. The treated cloth is squeezedthrough rubber rollers to 100 percent weight pickup of solution andthereafter dried at about 80 C.85 C. The dried cloth is thereafter heataired at 150 C.155 C. for approximately 3 minutes. Following this, thefabric is rinsed with cold water, boiled for approximately 10 minutes inthe presence of a small amount of non-ionic detergent and rinsed againin cold water. Chemical analysis (Kjeldahl method) of the treated clothindicates that approximately 83 percent of theN-hydroxymethylpyrrolidone-2, over and above that lost by sublimation(approximately 36 percent), is introduced into the treated cloth.

EXAMPLE 2 Example 1 is repeated except that the cotton print cloth isreplaced by a sample of Dacron-ccitton (60/40) fabric. Results s milarto those of Example I are obtained.

The fibrous materials obtained from Examples 1 and 2 are found to possesin comparison to untreated control samples of the foregoing fibrousmaterials, significantly improved receptivity for basic dyes, acid dyes,wool dyes, etc., which are conventially employed in dyeing wool, nylonand the like and which possess little or no affinity for untreatedcellulose materials. Further surprising is the discovery that thefibrous materials provided by the foregoing examples display, inaddition to the above mentioned properties, a pronounced aflinity forfluorescent brightening agents commonly employed with wool, nylon, etc.,as compared to untreated control samples of such fibrous materials.

The following examples illustrate the improved receptivity of fibrousmaterials which have been treated in accordance with the presentinvention to the above-mentioned dyestuffs and fluorescent brighteningagents.

EXAMPLE 3 The cotton print cloth obtained from Example 1 and theDacron-cotton (60/40) material obtained from Example 2 are each treatedseparately with an aminoooumarin fluorescent brightening agent of thefollowing formula:

The above compound is found to be substantive to each of the clothsamples which display a pronounced flourescent brightness in comparisonto untreated control samples of each of these fibrous materials.

As further illustrative of fluorescent brightening agents which may beused with fibrous materials treated according to the present inventionwith the intention of like re sults there may be mentioned by way ofexample the amino coumarins described in U.S. Patent 2,610,152, the 4,4di trizyldiaminostilbene 2,2 disulf nic acid derivatives described inU.S. Patent 2,612,501; the bis(2- morpholino 4 amino 1,3,5 triazyl (6)4,4- diaminostilbene sulfonic and carboxylic acid materials described inU.S. Patent 2,618,636; the hydroxybenzimido-azolylstilbene carboxyesters described in U.S. Patent 2,937,997; the 4,5-diphenylglyoxalone-disulfonic acid derivatives described in U.S. Patent2,691,653; and the brightening agents described in U.S. Patent2,688,777.

EXAMPLE 4 Samples of cotton print cloth, x 80, and Dacroncotton, 60/40)treated according to the process described in Example 1 are dyed at theboil with a 1 percent aqueous solution of the acid dyestuif Colour IndexAcid Yellow 121; C.I. No. 18690. The foregoing dyestuff exhibits apronounced affinity for each of the cloth samples treated therewithwhich exhibit a vivid overall yellow color. Control samples of theuntreated cloth materials exhibit negligible receptivity for the samedyestulf.

A similar improvement in receptivity to acid dyes, basic dyes, Wooldyes, etc., is obtained when samples of cotton print cloth andDacron-cotton (60-40), each treated in accordance with Example 1, areseparately dyed at the boil with aqueous solutions (1 percent) of thefollowing dyestuffs.

Colour Index- Acid Red 182 Acid Blue 179 Acid Black 107 Acid Orange 60Acid Red 273 Acid Red 114; OJ. No. 23635 Acid Blue 62; Cl. No. 62045Acid Green 25; Cl. No. 61570 Acid Black 48; Cl. No. 65005 Acid Orange72; Cl. No. 18740 Acid Red 183; CI. No. 18800 Acid Black 52; H. No.15711 Basic Red 14 Basic Red 13;C.I. No. 48015 Basic Red 15 Basic Blue5; Cl. No. 42140 Basic Orange 22; Cl. No. 48040 In each case, the sampesof treated cloth exhibit a pronounced receptivity for each of the abovedyestuff materials in comparison to control samples of untreated clothwhich exhibit but negligible receptivity therefor.

As stated previously, although the above dyestuif products are commonlyused in coloring fibrous materials comprising wool, nylon, acrylicmaterials and the like, they ordinarily display but negligible affinityfor untreated fibrous materials consisting in whole or in part ofcellulosic substances. However, by the process of the present invention,there are provided improved fibrous materials which are characterized bya pronounced aflinity for such acid, wool, and basic dyestulfs and thelike, as well as a pronounced affinity for fluorescent brighteningagents such as of the type hereinbefore indicated.

Furthermore, similar improved results as regards dye and fluorescentbrightener receptivity are obtained when the procedure of Example 1 isrepeated utilizing similar weight proportions of catalyst and lactammaterial but wherein the following compounds are substituted for theN-hydroxymethylpyrrolidone-Z compound of Example 1.

Pyrrolidones N-methoxymethyl pyrrolidone-Z 3,3-dimethyl-N-hydroxymethylpyrrolidone-Z 3 ,3 ,5-trimethyl-N-hydroxymethylpyrrolidone-2 3,3 ,5-trimethyl-N-methoxymethylpyrrolidone-2 3-propyl,5-methyl-N-hydroxymethylpyrrolidone-Z PiperidonesN-hydroxymethylpiperidone-2 N-methoxymethylpiperidone-24,4-dimethyl-N-hydroxymethylpiperidone-26-propy1-N-methoxymethylpiperidone-24,4-dimethyl-N-ethoxymethylpiperidone-2 Epsilon-caprolactams3,3,S-trimethyl-N-hydroxymethyl-E-caprolactamN-hydroxymethyl-E-caprolactam N-methoxymethyl-E-caprolactam4,4-dimethyl-N-ethoxymethyl-E-caprolactam In each case, the samples ofcotton print cloth and Dacron-cotton (60-40) obtained with the abovecompounds according to the process of Example 1 exhibit pronouncedaflinity for the dyestuffs and fluorescent brightening agents of thetype enumerated hereinabove.

As previously pointed out, the fibrous materials provided by the processof the present invention are additionally characterized by animprovement in such other properties, such as resistance to attack bymildew as will be apparent from the following example:

EXAMPLE 5 Samples of cotton print cloth, 80 x80 and Dacron-cotton(60/40) each treated in accordance with the process of Example 1 aresubjected, along with untreated control samples of the foregoingmaterials, to soil burial tests for a period of approximately two weeks.In each case, the treated cloth samples exhibited improved resistance tomildew as compared to the untreated samples.

It has also been found that the cellulosic materials treated inaccordance with the present invention are capable of complexing orcompounding with a variety of germicidal agents such as iodine andreducing the vapor pressure of the germicidal agent so that it remainson the cloth for substantial periods of time. The combination of iodineand other germicidal and disinfecting agents with cloth treated inaccordance with the present invention to produce germicidal bandages,surgical dressings, and the like, forms the subject matter of thecopending application of Leon Katz, filed Oct. 22, 1965, Ser. No.502,618, now Patent 3,401,006 which most fully describes and claims thesame.

While the invention has been described in particularity with respect tocertain embodiments thereof, it will be obvious to those skilled in theart that numerous modifica tions and variations of the invention can bemade without departing from the spirit and scope thereof. Therefore, itis intended that in the claims which follow the invention be interpretedas inclusive of all such modifications and variations insofar as thestate of the art permits.

What is claimed is: v

1. A process comprising treating fibrous materials containing labilehydrogen atoms with a composition consisting essentially of a compoundselected from the group consisting of lactam derivatives of the formula:

and ring carbon-lower alkyl substituted derivatives thereof, and whereinR represents a lower alkylene group necessary to complete a 5 to 7membered heterocycle and R is selected from the group consisting ofhydrogen and lower alkyl, and an acid catalyst contained in an aqueousmedium, then drying and curing the fibrous material at a temperature ofat least about C.

2. A process as defined in claim 1 wherein the fibrous material containsa cellulosic material.

3. A process as defined in claim 1 wherein the lactam derivative isN-hydroxymethylpyrrolidone-2-.

4. A process as defined in claim 1 wherein the lactam derivative isN-hydroxymethylpiperidone-2-.

5. A process as defined in claim 1 wherein the lactam derivative isN-hydroxymethyl- -caprolactam.

6. A process as defined in claim 1 wherein the lactam derivative isN-methoxyrnethylpyrrolidone-2-.

7. A process according to claim 1 wherein the acid catalyst isZ-methyl-Z-amino-l-propanolhydrochloride.

8. A fibrous material produced according to the process of claim 1.

References Cited UNITED STATES PATENTS 1,070,588 12/1959 Germany.

GEORGE F. LESMES, Primary Examiner J. CANNON, Assistant Examiner

